Symmetry-adaptive ferroelectric mesostates in oriented Pb(BI1/3BII2/3)O3-PbTiO3 crystals

An intermediate orthorhombic ferroelectric phase has been found in oriented crystals of (0.92)Pb(Zn1/3Nb2/3)O-3-0.08PbTiO(3) (PZN-PT 92/8). Investigations have been performed by electrically induced polarization and strain methods, and reciprocal phase space mapping. The lattice parameters of this intermediate ferroelectric state have been shown to be equal to those predicted by the adaptive martensite theory. A hierarchy of symmetries is believed to exist on the mesoscale which are due to symmetry reductions by domain averaging. (C) 2000 American Institute of Physics. [S0021-8979(00)07219-4].